Pearling/ph

[haowin]

Hi, just wondering if anyone can shed some light.
Ive got java ferns, vallis, anubias densa, elodea densa, riccia fluations.
At the moment my plants arent pearling, ive turned off my air pump to allow the plants to absorb as much co2 as possible, turning it back on after lights out, so im quite hesitant about the lack of supply of oxygen for the fish, they're not piping so it should be ok.

Can Ph affect pearling?
My ph is at 8, although im quite skeptical, ive got a test kit that says 8 ph isnt an optimal level for co2 or something but it would make sense, whenever i do a water change, the plants start pearling noticeably (the tap water comes out at 7.5) The heaviest pearling ive witnessed was about 40% water change, the java ferns didnt half pearl. (is it natural for it to pearl on both sides?)

Am i lacking something thats available in tap water?
Im currently dosing tropica nutrition (I read the + version is only need when the relation of fish bi-product to plants isnt enough)
2x45w light, with diy co2.

So im guessing its either the ph or something lacking thats available in tap water?

 

[RadaR]

It's not the pH that's causing it.
First lets run through what pearling is. Pearling indicates that the water surrounding the leaves is fully saturated with oxygen, no more can go into solution, so you get a visible bubble of gas. We see pearling mainly in high tech tanks because the plants are photosynthesising like mad because they're getting lots of light, CO2 and nutrients.
Tapwater contains decent levels of CO2 (why the pH is lower when it straight comes out the tap) and also oxygen. So, when you do a water change, the concetraion of CO2 and oxygen goes up in the tank. Plants possibly photosynthesis more and/or the small layer of water around the leaves become saturated with oxygen. Any more production of oxygen will show as bubbles.
Remember when you first filled the tank up? Remember all those bubbles on the wall?
Hope this helps.

 

[haowin]

yea, boxes off quite a bit. So im guessing with the majority or planted tanks the ph is going to be higher than neutral. Would explain my reading of 8 (if the plants are absorbing the co2 faster than the fish can exert it)
So it'd be safe to turn the pump on till i see the plants pearling, in which case the tank should be fully stocked on oxygen
Btw, doesnt my tank constitute the requirements needed to see the plants pearling? Its nearly 3wpg, so should be producing neough light to easily sustain all the plants, Not sure how to measure the co2 accurately, but probably 1.5-2 bub/sec, without considering the fish.
Is it possible that im lacking an important nutrition?

Thanks for the help

 

[mark4785]

Be cautious when turning your airstone off. I turned mine off in the hope that c02 levels would rise and the oxygen levels must have changed so quickly that one of the inhabitant fish died. Think about the fish before the plants.

edit: it would seem your PH level indicates a lot of C02 is being converted into oxygen so you may not run into the same issues I did but still be very cautious when cutting the supply of oxygen.

 

[RadaR]

Be cautious when turning your airstone off. I turned mine off in the hope that c02 levels would rise and the oxygen levels must have changed so quickly that one of the inhabitant fish died. Think about the fish before the plants.

edit: it would seem your PH level indicates a lot of C02 is being converted into oxygen so you may not run into the same issues I did but still be very cautious when cutting the supply of oxygen.

This hasn't been proven to be the fish death It's just a theory of yours.
You seem very hung up on CO2 and oxygen balance. A tank can exist to have good CO2 levels and good O2 levels at the same time (that's what we strive for). It can also exist to have low CO2 and low O2. If one is up, it doesn't mean the other is down.